The invention relates to a fluid mechanical converter having at least one energy-accumulator mass system that can be powered by a power drive.
A generic fluid mechanical converter is known, for example, from BIONA report 12 (Gustav Fischer Publishers, Stuttgart, 1998). In this publication on the occasion of the Fourth Bionic Congress 1998 in Munich, Hans Scharstein, in a paper entitled title “Balance of Force and Power in Artificial Wing Motion of Individual Insect Wings,” describes a piezo wing power drive. In this familiar device, a propeller is rotatably mounted on a piezo flexion element, which as a first spring-mass system, executes a striking motion, where the powering of the first spring-mass system advantageously occurs in resonance. To make possible a continual fluid stream to one side, the batting arm that forms the second spring-mass system is rotated passively against a rotary spring by the emerging air forces. As a result of this arrangement, a rotation of the propeller is introduced at every turnaround point of the oscillating motion.
As a result of the inertia of the batting arm and of the small air forces in the turnaround points, this rotation occurs with a delay, so that the batting arm is not yet in optimal rotation position shortly after the turnaround point of the strike swiveling. Consequently the total degree of effectiveness of the device is reduced.
WO 00/53935 A1 reports a device for producing a fluid stream, in which device a wing element mounted on a rotation body can be converted into a first up-and-down motion by means of the resonator that powers the rotation body. For simulating the striking motion of an insect wing, this known device comprises an additional power unit that is indirectly coupled with the wing element and by means of said unit a second motion, namely a rotation of the wing element, can be wound up around its longitudinal axis and is overlaid on the first up-and-down motion of the wing element.
Through the use of two separate power drives for producing the two oscillating motions of the wing element overlaid on one another, this device is very complex in terms of construction and control technology.
In addition, a device configured as a fluid mechanical converter (FMC) with a non-rotary motion that is, for example, with oscillating parts, is known for instance from EP 0 733 168 B1, and concerns a ventilator for distributing generated heat of an appliance. The ventilator comprises a flexible wing element that has first and second ends and is powered by electromagnetic forces, so that the position of the wing element is constantly monitored by a Hall effect appliance. Fluid machines of this type are complex in terms of the adjustment device and are characterized by simply constructed moving mechanical parts, which operate with only minor losses. The wing element, on the other hand, operates with a low aerodynamic degree of effectiveness because the fluid effect breaks down very early because of the uncontrolled motion of the wing element. The energy transmission from the wing element to the surrounding fluid is prone to severe losses, and thus the overall degree of effectiveness of the ventilator is poor and the effect in addition can be loud noises during operation.
In addition, in EP 0 517 249 A2, a device is described which produces a two-dimensional flow of a fluid with a high efficiency and low noise levels by imitating the buzzing of bees with a special mechanism. Devices of this type are distinguished by a high aerodynamic effectiveness because the flow continues longer. Less advantageous are the more complex structure of the power shaft and the related high friction of the power joints, the relatively high noise build-up and the structural size of the device.
It is consequently the object of the present invention to create a fluid mechanical converter of the aforementioned type, which improves the total degree of effectiveness while using the simplest components.